Doctors at the University of Pennsylvania School of Veterinary Medicine’s New Bolton Center removed a 15-inch external growth from the intestines of 2012 Belmont Stakes runner-up Paynter, owner Ahmed Zayat confirmed Oct. 3.

The 3-year-old colt, who has been battling illness since late August, went into surgery around 9:15 a.m. EDT and was in recovery by approximately 1 p.m. EDT. Louise Southwood, BVSc, PhD, Dipl. ACVS, ACVECC, associate professor in the Department of Clinical Studies at New Bolton Center, who headed up the operation, said he woke up from the anesthetic and stood "like a champ."

Paynter began spiking fevers after his last race and had been hospitalized at Upstate Equine Medical Center in Schuylerville, N.Y., since the week of Aug. 26 while fighting an infection of his colon, and later, a bout of laminitis in three feet. After recovering from the laminitis, he was transported to New Bolton in Kennett Square, Pa. on the afternoon of Oct. 2 to be operated on by Southwood, a leading equine intestine surgeon and specialist in the area of colitis.

"Just think about the resilience of this guy," Zayat said